The Transgenic/Gene Knockout Facility was developed to provide the physical resources and technical expertise for generation of transgenic and gene knockout mice for the research needs of the EHS Center members. The facility is directed by Dr. Ye-Shih Ho. As proposed, the facility could provide complete handling of a project, from isolation of a cDNA to construction of the expression gene to screening of the F0 pups to identifying animals carrying the transgene. Dr. Ho proposes to provide nine services to investigators from the Center; these include: 1) design and construction of expression vectors for generation of transgenic animals; 2) preparation of DNA for microinjection; 3) maintenance of stock mice and various lines of transgenic and knockout mice; 4) microinjection of DNA into fertilized eggs and surgical implantation of the microinjected embryos into pseudopregnant recipients; 5) screening and identifying of transgenic mice; 6) assistance on construction of gene targeting vector and culturing and screening of ES cells; 7) microinjection of mouse blastocysts with ES cells for generation of gene knockout mice; 8) training in the production of transgenic mice; and 9) consultant support for individuals who propose to use transgenic or gene knockout animals. This facility is located in the ICT and consists of two animal rooms that house stock animals, a surgical suite with two microinjection stations, and an additional room containing two CO2 incubators. As proposed, the facility would bill principal investigators only for the cost of consumables. Dr. Ho proposes to produce four transgenic F0 animals per project.